Aspal Roads is produced from coal, it can also be produced from petroleum or wood. Asphalt is produced in a plant that heats, dries and mixes aggregate, bitumen and sand into a composite mix. It is then applied through a paving machine on site as a solid material at a nominated or required thickness, relative to the end use.
Concrete Roads These are made of concrete (cement+water+sand+aggregates) are created using a concrete mix of Portland cement, coarse aggregate, sand and water. In virtually all modern mixes there will also be various admixtures added to increase workability, reduce the required amount of water, mitigate harmful chemical reactions and for other beneficial purposes.
In almost all the new major road construction you can see the use of concrete rather than asphalt these days. At the same time, some popular highways are still in asphalt.
Advantages of Concrete Roadways
- Durability and maintenance free life: Concrete roads have a long service life of forty years, whereas asphalt roads last for ten years. More over, during this service life concrete road do not require frequent repair or patching work like asphalt roads.
- Vehicles consume less fuel: A vehicle, when run over a concrete road, consumes 15-20% less fuel than that on asphalt roads. This is because of the fact that a concrete road does not get deflected under the wheels of loaded trucks.
- Resistant to automobile fuel spillage and extreme weather: Unlike asphalt roads, concrete roads do not get damaged by the leaking oils from the vehicles or by the extreme weather conditions like excess rain or extreme heat.
- Greener process: Asphalt (bitumen) produces lots of highly polluting gases at the time of melting it for paving. Also, less fuel consumption by the vehicle running on a concrete road means less pollution.
- Saving of natural resources: Asphalt (bitumen) is produced from imported petroleum, the reserve of which is becoming reduced drastically. On the other hand, concrete (cement) is produced from abundantly available limestone.
Disadvantages of Concrete Roadways
- Paving cost: The paving cost of the concrete road is little higher compared to asphalt paving.
- Maintenance Problem: In case the concrete road breaks, the whole concrete slab needs to be replaced.
- Safety features: In rainy and the winter season vehicles tend to slip or slide on concrete road due to rain and snow.
Advantages of Asphalt (Bitumen) Road
- Economical: Asphalt is still less costly compared to concrete. Moreover, it takes less time to build a asphalt road than a concrete road. (Asphalt dries faster.)
- Recyclable: Asphalt is a recyclable material. It can be used again and again by melting it.
- Easy maintenance: Repairing just a prt of the asphalt road is easily possible. Asphalt roads even can be relayered over the old layer.
- Safe: Asphalt roads provide better traction and skid resistance for vehicles. Asphalt tends to help keep roads free from ice and snow.
Disadvantages of Asphalt (Bitumen) Road
- Durability: heavy rain and other extreme weather conditions damage the asphalt road, and the roads need to be repaired frequently.
- Weather Pollution: Melting asphalt produces lots of harmful green house gases. Also costly petroleum is required to produce asphalt.
Remark
Concrete roads are highly durable and more environmentally friendly as compared to asphalt roads. However asphalt paving costs far less than concrete paving. Also, asphalt road provides a little better safety of the vehicle against snow and skidding.